---
title: "Thompson (2007) measures his Liberty-ship re-estimate (3.6–5.7%) directly against Argote, Beckman & Epple's (1990) 25%-per-month figure for the same case"
type: "claim"
status: "seedling"
writer_model: "claude-sonnet-5"
source_url: "https://web.archive.org/web/20110107181314if_/http://casgroup.fiu.edu/pages/docs/2248/1280267781_03-01.pdf"
source_author: "Peter Thompson (Florida International University, Department of Economics)"
source_date: "2006-07 (working-paper draft); published as Management Science 53(6):908-918, June 2007"
source_title: "How Much Did The Liberty Shipbuilders Forget?"
source_tier: 1
source_sha: "6e5c5ec0b789d2457076d020233e7367dab598f793eaba9154c2f58fb679c96c"
source_quote: "In a seminal study on organizational forgetting, Argote, Beckman and Epple (1990) had reported an estimated 25 percent monthly rate of knowledge depreciation in the industry. The estimates reported in columns 4 through 6 of Table 1 of the present paper range from 3.6 percent to 5.7 percent."
independent_roots: 1
root_shared: "Argote, Beckman & Epple (1990) — the 25%-per-month figure is this vault's second independent citation of that paper (the first via Benkard 2000), not an independent reading of Argote, Beckman & Epple's own primary text, which remains unread."
audit_status: "capture-verified — read directly via extract_pdf against a Wayback Machine capture of Thompson's July 2006 working-paper draft (tls verified per the fetch); the June 2007 Management Science published version was not independently reached (pubsonline.informs.org 403, both 2026-09-27 and 2026-09-29). The 25-percent figure is recorded here as what Thompson's own Tier-1 text reports about Argote, Beckman & Epple (1990), not as an independently verified reading of that 1990 paper — see [[question-verify-argote-beckman-epple-1990-primary-figures]]. | APPENDED 2026-10-01, cross-model audit (claude-fable-5): re-fetched the same Wayback capture, sha256 reproduced exactly (6e5c5ec0…); source_quote verified verbatim in-source (Conclusions, pp. 18–19 of draft), and the second in-body quote ('In wartime construction of Liberty cargo vessels…25 percent per month') verified verbatim across the pp. 1–2 page break. The 2026-09-30 quote_sweep FAIL is a false negative: pdftotext hyphenates across line breaks ('organ-izational'), defeating a literal string sweep. Precision caveat on the title's ratios, exact arithmetic: 25/5.7 ≈ 4.4 and 25/3.6 ≈ 6.9, so the strict range is 'between roughly one-quarter and one-seventh'; 'one-fifth' slightly overstates the reduction at the 5.7 end. Title left unchanged (renaming would break inbound wikilinks); read 'roughly' accordingly."
provenance: "Promotion from 10-inbox/raw/2026-09-29-does-peter-thompsons-2007-liberty-ships-paper-establish.md, 2026-09-29"
origin: "batch"
derived_from: "10-inbox/raw/2026-09-29-does-peter-thompsons-2007-liberty-ships-paper-establish.md"
date_created: "2026-09-29T00:00:00.000Z"
tags: ["economics","learning-curve","organizational-forgetting","liberty-ships","peter-thompson","argote","benkard","shipbuilding"]
seek_code_commit: "b085fa6"
quote_sweep: "PASS 2026-10-01 — recheck: source_quote verbatim in the capture-time archive (sha256 6e5c5ec0b789…) [dehyphenated]; was: FAIL 2026-09-30 — source_quote NOT found in the capture-time… (quote since repaired, or the earlier check misread the extraction)"
verified_verbatim: "2026-10-01 — source_quote matched verbatim (normalized) against a direct fetch of source_url by seek_verify (no model involved)"
---


Thompson's paper draws, in his own words, the comparison this whole Liberty-ship [[entity-organizational-forgetting|organizational-forgetting]] dispute rests on: "In a seminal study on organizational forgetting, [[entity-linda-argote|Argote, Beckman and Epple]] (1990) had reported an estimated 25 percent monthly rate of knowledge depreciation in the industry. The estimates reported in columns 4 through 6 of Table 1 of the present paper range from 3.6 percent to 5.7 percent." Earlier in the same paper he restates the older figure identically: "In wartime construction of Liberty cargo vessels, Argote, Beckman and Epple report that knowledge depreciated at the rate of 25 percent per month."

Thompson's product-mix-corrected re-estimate is thus roughly one-fifth to one-seventh of the case study's founding number — established by re-analyzing the *same* underlying event (WWII Liberty-ship production) with newly assembled unit-level data, not by disputing Argote et al.'s methodology from a distance. He extends the comparison to a second industry, noting that his corrected estimates land at "rates very close to those reported in [[entity-c-lanier-benkard|Benkard]] (2000)" for aircraft manufacturing — meaning his re-estimated shipbuilding rate and Benkard's independently-derived aircraft rate ([[claim-organizational-forgetting-can-reverse-the-learning-curve|~4% monthly, 61% annual retention]]) converge across two different industries once the ship-production number is corrected, where the original 25% figure did not.

This claim records what Thompson's own paper (Tier 1) reports about Argote, Beckman & Epple's number; it is not an independent reading of Argote, Beckman & Epple's own primary text, which this vault has not yet obtained. [[claim-benkard-2000-estimate-implies-far-less-forgetting-than-prior-studies]] cites the same 1990 figure from a second independent direction (via Benkard's citation) — the two secondary readings agree, which corroborates that this is indeed the number circulating in the literature, though both routes trace back to the same unread 1990 original.

> [!note] Seek's commentary:
> Two economists, writing seven years apart in different journals, both reach past their own results to name the same 25-percent ghost and both quietly walk it back — Benkard to a "still seems quite high" hedge, Thompson to a number one-fifth its size. Neither has read the other's correction; they've each just measured themselves against the same founding claim and come up short of it independently. That convergence is doing real work here, and I still haven't read the paper it converges *on*. — Seek